Safety closures

ABSTRACT

A safety closure with an outer ring mounted over the threaded cap for a bottle with an annulus extending in from the outer ring engageable in a groove on the outer surface of the cap and with a clutch engagement between the annulus and the side of the groove at one limit and preferably the upper limit of axial movement between the ring and the cap.

United States Patent Petronelli et al.

[ 51 June 13, 1972 SAFETY CLOSURES Inventors: Claudio Petronelli, 45Koromiko Road; Gavin Muldrew Park, 192 Comfoot Street, both of Wanganui,New Zealand Filed: June 16, 1970 Appl. No.: 46,697

Foreign Application Priority Data June 19, 1969 New Zealand ..156850Oct. 28, 1969 New Zealand ..l58232 U.S. CL... ..2l5/9 Int. Cl M1161]1/00, 865d 55/02 Field of Search ..215/9, 43 A, 83, 44

References Cited UNITED STATES PATENTS 2,487,728 11/1949 Quiring ..215/9Primary Examiner-George T. Hall Attorney-Holman and Stern [57] ABSTRACT11 Claims, 7 Drawing Figures SAFETY CLOSURES This invention relates tosafety closure means and/or methods of manufacturing said safety closuremeans.

Safety closures for containers are known but as yet are not in generaluse. We believe that the complexity of construction and assembly ofknown safety closures results in excessive and impractical manufacturingcosts. Also the more complex the engineering the more likely there is tobe some failure during the life of the safety closure. Finally, manyclosures are so difficult to manipulate that even an adult user may havetrouble in gaining access to the container.

It is therefore an object of the present invention to provide a safetyclosure and/or methods of manufacturing said safety closure which willsubstantially reduce the above-mentioned disadvantages or at leastprovide a useful choice over safety closures already known.

Accordingly in one aspect the invention may broadly be said to consistin a safety closure for containers having a neck threaded internally orexternally said closure means comprising an inner capor cup-shaped partadapted to screw on or into the neck of said container and an outerring-shaped part mounted on said inner part, said inner and outer partsbeing capable of limited relative axial movement and rotationally beingfree from each other except when deliberately moved to the limit ofrelative axial movement, such movement in one direction causing theengagement of a clutch comprising in turn a component on the inner partand a component on the outer part, said components being adapted torotate together as to cause a rotary unscrewing motion imparted to thering, to be transmitted to the cap when the two caps are moved to oneaxial limit and are held firmly at the limit of movement.

One preferred form of the invention and modifications thereof will nowbe described with reference to the accompanying drawings in which FIG. 1is a cross section of the outer part of the first embodiment of a safetyclosure according to the present invention.

FIG. 2 is a side elevation of the inner part according to said firstembodiment.

FIG. 3 is a cross section through the outer part of a second embodimentof the safety closure.

FIG. 4 is a side elevation of the inner part according to the secondembodiment.

FIG. 5 shows the two parts of FIGS. 3 and 4 assembled.

FIG. 6 is a perspective exploded view of the parts of FIGS. 3

and 4, and

Q 2 the safety closure means consists of an inner part formed as a cupor cap 1 adapted to screw over or into the neck of a container andsurrounding the inner part 1, an outer part 2 consisting of a ring orhollow cylinder without ends. The outer part has, projecting inwardsfrom its inner surface an annulus or ridge 3. This ridge 3 fits within awide groove 4 on the outer cylindrical surface of the inner part. Theinner diameter of the ridge 3 is less than the diameter of the groovebut greater than the diameter of the annuli or ridges 5 and 6 whichbound the groove 4. The axial length of the ridge is considerably lessthan that of the groove. The ring 2 is thus free to rotate on the cup 1and to move a limited distance axially relative to it but cannot beremoved from it without using destructive force.

The outer ring 2 and the inner part or cap 1 are so proportioned thatwhatever the position of the ring it completely covers the cylindricalsurface of the cap and only the ring can be grasped by the hand.

When the safety closure is assembled the cap can be removed from thebottle only by using the ring 2 to unscrew it. For this purpose a clutchis formed by co-operation between the ridge 3 projecting inwards fromthe ring 2 and the upper ridge 5 bounding the groove 4 of the cap. Theclutch is a modified form of dog clutch. The mating surfaces of the tworidges which cooperate to form the clutch are formed into abutments eachextending over a quarter of a circumference.

When the abutments are interlocked the clutch is engaged and the sleevewill drive the cap so as to unscrew it. Otherwise the sleeve rotatesfreely.

The clutch cannot easily be engaged accidentally. The faces 7 and 8 arenot parallel to the axis of the neck of the bottle but are sloped at anangle, for example an angle of 20 55 so that the rotation of the sleevewill not maintain engagement of the clutch unless the two parts are heldfirmly together, that is, the inclined surfaces tend to disengage theclutch unless a substantial force is exerted by the user moving theinclined faces into engagement.

The unscrewing clutch is provided at the upper axial limit of movementallowed between the ridge 3 and groove 4 and this, while being acomparatively simple manipulation by an adult, is an unnatural movementfor a person intending to unscrew the safety closure thereby minimizingthe risk of any child gaining access to the contents of a bottle usingthe safety closure according to the present invention.

In the preferred embodiment of the invention the outer comer 9 of theabutment 7 is rounded, further assisting in the disengagement betweenthe two faces unless the positive upward force is exerted. Also thesurface 10 is sloped back at an acute angle as illustrated in FIG. 2while the surface from the top of the abutment face 8 is at right anglesto the axis of the safety closure. This provides a ratchet action andfurther assists in a tendency to disengage the abutment faces 8 and 9unless the upward force is exerted.

Accordingly the co-operative surfaces 7 and 8 of the clutch between thecap I and the sleeve 2 form a species of ratchet which will freewheelreadily except when the sleeve is held firmly up against the upper ridge5 and is rotated so as to unscrew the cap.

It will be understood that the ratchet means hereinbefore described inwhich the working faces are so inclined as to facilitate disengagementmay be embodied in forms other than the peripheral ridges herebeforedescribed in the preferred embodiment.

The upper surface 11 of the ridge 3 is chamfered or inclined at an angleof approximately 45 from the inner surface of the outer ridge 3. Acomplementary chamfered portion I2 is provided on the lower surface ofthe ridge 6. The components are arranged so that there is aninterference fit between the ridge 3 and the ridges 5 and 6. Toleranceof fit between the two members is arranged so that when the members arehot and an axial force is exerted the ridge 6 may be forced past theridge 3 leaving the ridge engaged in the groove between the ridges 5 and6 for the closure to operate as above described. In the preferredembodiment the two parts of the closure means are moulded from asuitable plastics which may be different for the two parts so that therelative co-effients of expansion will assist with the engagement asoutlined above.

The two components would be manufactured separately and would beassembled as above described, for example while the components werestill hot after release from the mold. Alternatively the componentscould be heated and assembled again as above described.

In another preferred form of the invention as illustrated in the FIGS. 3to 7 the safety closure cap comprising the inner cup or cap 1 and outerring 2 is again provided with a similar arrangement for engagement andwith the unscrewing clutch means as previously described. In thisembodiment reference numerals similar to those used in connection withthe same components in the embodiment described with reference to FIGS.1 and 2 are again used.

In this embodiment a second clutch is provided to allow the outer ringto be engaged to screw the cap firmly back on to the bottle. In thisinstance the clutch is provided between the lower face of the ridge 3and the upper face of the ridge 6. As it is not objectionable thataccidental rotation of the sleeve should tighten the cap, the design ofthe faces that co-operate for tightening is such that engagement is notdiscouraged. At each quarter of the circumference there is a step 13 inthe ridge 6 of the cap and a step 14 in the ridge 3 of the sleeve.

The plane of these steps is parallel to the axis of the parts so thatthey engage firmly with little axial pressure. Engagement is encouragedby sloping the surface from the head of one step to the foot of theprevious abutting face. Thus ratchet action is provided both on theridge 3 and ridge 6 and ensures as far as possible that little torquewill be transferred to the cap 1 to unscrew the cap even when an axialforce is exerted tending to engage the second clutch. The secondembodiment of the invention is assembled in a similar way to thatpreviously described with the first embodiment.

If a child has access to a bottle with a safety closure according to thepresent invention and tries to open it, it will find that by using anormal unscrewing action, neither clutch means will engage to provide asignificant force in the direction which would unscrew the cap. Even ifthe child performs the natural act of pressing the two parts togetherand unscrewing, the ratchet between the lower clutch means will allowthe ring to freewheel.

The cap can be removed only by the rather difficult process of raisingthe ring relative to the bottle and maintaining a firm upward axialpressure while unscrewing the cap 1. The sophistication needed for thissequence of operation is such that a bottle closed by a safety closureaccording to the present invention will obviate or minimize thelikelihood of the cap being removed by a child.

What is claimed is:

1. A safety closure for a container having a neck including a threadedportion, closure means comprising an inner cap or cup-shaped part toscrew relative to the neck of said container, and an outer ring-shapedpart mounted on said inner part, clutch means comprising a component onsaid inner and outer parts, said inner and outer parts including meanslimiting relative axial movement and rotationally being free from eachother except when deliberately moved to the limit of relative axialmovement, such movement in one direction causing the engagement of saidclutch means, said clutch means components being engageable to rotatetogether to cause a rotary unscrewing motion imparted to the outer partto be transmitted to the inner part when the two parts are moved to oneaxial limit and are held firmly at the limit of movement.

2. A safety closure as claimed in claim 1 wherein said clutch meanscomprises buttresses on said outer part and said inner partrespectively, said buttresses having working faces so inclined to theaxial direction as to permit the two parts to slip out of engagementunless they are held firmly together.

3. A safety closure as claimed in claim 2 wherein an annulus is providedextending in from the inner surface of said outer part and an annulargroove provided on the outer surface of said inner part with the axiallength of said annulus substantially less than that of the groove, andwith the clutch means provided between the co-operating faces of theridge and the side of said groove.

4. Apparatus as claimed in claim 3 wherein said clutch means forimparting an unscrewing motion from said ring to said inner part isprovided between the top face of said annulus or ridge on the outermember and the upper or top side of the groove of the inner member,thereby requiring an upward axial movement to engage the clutch.

5. Safety closure as claimed in claim 4 wherein the mating surfaceswhich co-operate to form the clutch means are formed into a plurality ofabutments of co-operating faces which are not parallel to the axis ofthe neck of the bottle but are sloped at an angle so that rotation ofthe sleeve will disengage the clutch unless the two parts are heldfirmly together.

6. Safety closure as claimed in claim 5 wherein the outer corner of theabutment face is rounded, further assisting in disengagement between thetwo members unless the axial engagement force is retained.

7. A safety closure for containers having a neck including a threadedportion, closure means comprising an inner cap or cup-shaped part toscrew relative to the neck of said container, andan outer ring-shapedpart mounted on said inner part, said inner and outer parts includingmeans limiting relative axial movement and rotationally being free fromeach other except when deliberately moved to the limit of relative axialmovement, such movement in one direction causing engagement of a firstclutch comprising buttresses on said outer part and buttresses on saidinner part engageable together to cause a rotary unscrewing motionimparted to the outer part to be transmitted to the inner part when thetwo parts move to the upper axial limit and are held firmly at the limitof the movement, and a second clutch comprising buttresses on said outerpart and buttresses on said inner part engageable together to cause arotary screwing motion imparted to the outer part to be transmitted tothe inner part when the two parts move to the lower axial limit but withratchet means between said buttresses to prevent any engagement of thesecond clutch tending to unscrew the inner part.

8. Safety closure as claimed in claim 7 wherein the shutment faces orsteps in the second clutch are parallel to the axes of the respectiveparts so that engagement will take place with little axial pressurebeing inserted by the user.

9. Safety closure as claimed in claim 8 wherein the surfaces between theoutermost point of the abutments are inclined to the foot of the nextabutment thereby providing a ratchet which will disengage the secondclutch upon a movement tending to unscrew the cap.

10. A safety closure for container having a threaded neck, said closuremeans comprising an inner capshaped part to screw onto the neck of thecontainer, an annular groove provided in the outer surface of the innercap part, an outer ring shaped part mounted on said inner part, anannulus extending in from the inner surface of said outer ring part toengage within said annular groove with the axial length of the annulussubstantially less than the axial length of the groove and with the ringrotationally free from the inner part except when deliberately moved tothe limit of the relative axial movement with the outer part coveringthe cylindrical surface of the inner part irrespective of the axialposition thereof such movement in one direction causing the engagementof a clutch comprising in turn buttresses on the inner part andbuttresses on the outer part, said buttresses being engageable to rotatetogether to cause a rotary unscrewing motion imparted to the outer partto be transmitted to the inner part when the two parts are moved to oneaxial limit and are held firmly at the limit of movement.

11. A safety closure as claimed in claim 10 wherein an inclined face isprovided on the annulus extending in from the outer ring part and acomplementary inclined face is provided on an outer rim of the innerpart so that engagement between said separately formed inner and outerparts having an interference fit between the rim and the annulus isfacilitated.

i t i

1. A safety closure for a container having a neck including a threadedportion, closure means comprising an inner cap or cupshaped part toscrew relative to the neck of said container, and an outer ring-shapedpart mounted on said inner part, clutch means comprising a component onsaid inner and outer parts, said inner and outer parts including meanslimiting relative axial movement and rotationally being free from eachother except when deliberately moved to the limit of relative axialmovement, such movement in one direction causing the engagement of saidclutch means, said clutch means components being engageable to rotatetogether to cause a rotary unscrewing motion imparted to the outer partto be transmitted to the inner part when the two parts are moved to oneaxial limit and are held firmly at the limit of movement.
 2. A safetyclosure as claimed in claim 1 wherein said clutch means comprisesbuttresses on said outer part and said inner part respectively, saidbuttresses having working faces so inclined to the axial direction as topermit the two parts to slip out of engagement unless they are heldfirmly together.
 3. A safety closure as claimed in claim 2 wherein anannulus is provided extending in from the inner surface of said outerpart and an annular groove provided on the outer surface of said innerpart with the axial length of said annulus substantially less than thatof the groove, and with the clutch means provided between theco-operating faces of the ridge and the side of said groove. 4.Apparatus as claimed in claim 3 wherein said clutch means for impartingan unscrewing motion from said ring to said inner part is providedbetween the top face of said annulus or ridge on the outer member andthe upper or top side of the groove of the inner member, therebyrequiring an upward axial movement to engage the clutch.
 5. Safetyclosure as claimed in claim 4 wherein the mating surfaces whichco-operate to form the clutch means are formed into a plurality ofabutments of co-operating faces which are not parallel to the axis ofthe neck of the bottle but are sloped at an angle so that rotation ofthe sleeve will disengage the clutch unless the two parts are heldfirmly together.
 6. Safety closure as claimed in claim 5 wherein theouter corner of the abutment face is rounded, further assisting indisengagement between the two members unless the axial engagement forceis retained.
 7. A safety closure for containers having a neck includinga threaded portion, closure means comprising an inner cap or cup-shapedpart to screw relative to the neck of said container, and an outerring-shaped part mounted on said inner part, said inner and outer partsincluding means limiting relative axial movement and rotationally beingfree from each other except when deliberately moved to the limit ofrelative axial movement, such movement in one direction causingengagement of a first clutch comprising buttresses on said outer partand buttresses on said inner part engageable together to cause a rotaryunscrewing motion imparted to the outer part to be transmitted to theinner part when the two parts move to the upper axial limit and are heldfirmly at the limit of the movement, and a second clutch comprisingbuttresses on said outer part and buttresses on said inner partengageable together to cause a rotary screwing motion imparted to theouter part to be transmitted to the inner part when the two parts moveto the lower axial limit but with ratchet means between said buttressesto prevent any engagement of the second clutch tending to unscrew theinner part.
 8. Safety closure as claimed in claim 7 wherein the abutmentfaces or steps in the second clutch are parallel to the axes of therespective parts so that engagement will take place with little axialpressure being inserted by the user.
 9. Safety closure as claimed inclaim 8 wherein the surfaces between the outermost point of theabutments are inclined to the foot of the next abutment therebyproviding a ratchet which will disengage the second clutch upon amovement tending to unscrew the cap.
 10. A safety closure for containerhaving a threaded neck, said closure means comprising an innercap-shaped part to screw onto the neck of the container, an annulargroove provided in the outer surface of the inner cap part, an outerring-shaped part mounted on said inner part, an annulus extending infrom the inner surface of said outer ring part to engage within saidannular groove with the axial length of the annulus substantially lessthan the axial length of the groove and with the ring rotationally freefrom the inner part except when deliberately moved to the limit of therelative axial movement with the outer part covering the cylindricalsurface of the inner part irrespective of the axial position thereofsuch movement in one direction causing the engagement of a clutchcomprising in turn buttresses on the inner part and buttresses on theouter part, said buttresses being engageable to rotate together to causea rotary unscrewing motion imparted to the outer part to be transmittedto the inner part when the two parts are moved to one axial limit andare held firmly at the limit of movement.
 11. A safety closure asclaimed in claim 10 wherein an inclined face is provided on the annulusextending in from the outer ring part and a complementary inclined faceis provided on an outer rim of the inner part so that engagement betweensaid separately formed inner and outer parts having an interference fitbetween the rim and the annulus is facilitated.